Angiogenic Imaging in Pulmonary Arterial Hypertension (AIPAH)

Inclusion Criteria:

• Age ≥18 years at screening;
• Documented diagnosis Group 1 PAH confirmed by resting mean pulmonary artery pressure greater than 25 mm of Hg, pulmonary vascular resistance greater than 3 Wood units, and pulmonary wedge pressure less than 12 mm of Hg measured by right heart catheterization at the time of diagnosis and before initiation of PAH specific therapy clinically stable for 60 or more days prior to enrollment, defined as no changes in medical regimen and no hospitalizations;
• Prior diagnosis of exercise-associated PAH (EPAH) confirmed by normal resting hemodynamics (mean pulmonary artery pressure < 25 mm of Hg, pulmonary artery wedge pressure < 12 mm of Hg, and pulmonary vascular resistance < 3 Wood units) measured by right heart catheterization at rest and abnormal hemodynamic response to exercise characterized by increase in mean pulmonary artery pressure > 30 mm Hg, pulmonary artery wedge pressure < 20 mm Hg, and pulmonary vascular resistance > 1 Wood unit at peak exercise and cardiac output less than 10 L/min before initiation of any PAH specific therapy. Patients need to be clinically stable for 60 or more days prior to enrollment, defined as no changes in medical regimen and no hospitalizations;
• Willingness to participate as evidenced by signing of the informed consent;

Exclusion Criteria:

• Prior history of chronic infectious disease, tuberculosis, or severe fungal disease; chronic hepatitis B or C infection; renal insufficiency; interstitial pneumonitis, bronchiectasis, or pulmonary fibrosis; known chronic pericardial effusion, pleural effusion, or ascites; chronic liver disease; myeloproliferative disorders in the past 5 years; non-basal cell malignancy or treated lymphoproliferative disease within the past 5 years; known HIV positive; life expectancy of <3 years;
• Chronic inflammatory condition such as lupus or rheumatoid arthritis, ulcerative colitis or Crohn's disease;
• White blood cell count <2,500/uL, hematocrit < 30 percent, or platelet count < 50,000/uL;
• Elevated liver transaminase levels (AST or ALT) 20 % above upper limit of normal (ULN) or albumin 20 % below the lower limit of normal (LLN);
• Creatinine clearance < 45 mL/min as estimated with the Cockroft-Gault equation;
• Women who are pregnant or breastfeeding;
• Men or women who plan to have children during the study period or who are unwilling to use effective forms of contraception;
• Known active cancer;
• Chronic use of oral steroid therapy or other immunosuppressive or biologic response modifiers (see Exclusionary Medication List in Manual of Operations). Eligible study participants will be encouraged to have up to date pneumococcal and influenza vaccinations as recommended based on their age and underlying medical conditions;
• Evidence of interstitial pneumonitis, bronchiectasis, or pulmonary fibrosis in the past 12 months by chest X-ray. For participants who have not had a chest X-ray during the 12 months prior to enrollment in the study, a chest X-ray will be obtained at baseline as part of the study protocol;
• New York Heart Association Class IV congestive heart failure;
• Severe asthma or COPD defined by FEV1 less than 50% predicted and FEV1/FVC less than 70% per PFTs in the past 12 months;
• Active tobacco use during the prior 10 years;